Thin film transistor-liquid crystal displays (TFT-LCDs) are currently the most widely used flat panel displays. As technologies for manufacturing liquid crystal panels are maturing and advancing, simplifying manufacturing processes, shortening the manufacturing processes, and improving efficiency of the manufacturing processes are important ways to reduce production costs so as to survive in fierce competition in the industry. Therefore, manufacturing a TFT-LCD array substrate structure using three photolithography processes has come into being.
The three photolithography processes are combined with a peeling process of a transparent electrode using a halftone mask based on four photolithography processes. After tunneling a passivation layer, the transparent electrode is directly formed without removing a photoresist. The photoresist is removed after forming the transparent electrode. Difficulty of the peeling process of the transparent electrode is that the photoresist is covered with the transparent electrode. The photoresist can only be peeled from an undercut area not covered by the transparent electrode using a stripping solution. In the area where the undercut is small, the peeling efficiency is low and the photoresist remains, thereby affecting panel quality.